diff --git a/auto/os/freebsd b/auto/os/freebsd
index 3a73a6e..7ddd6dc 100644
--- a/auto/os/freebsd
+++ b/auto/os/freebsd
@@ -3,7 +3,7 @@
 CORE_DEPS="$UNIX_DEPS $FREEBSD_DEPS"
 CORE_SRCS="$UNIX_SRCS $FREEBSD_SRCS"
 
-CFLAGS="$CFLAGS -pipe"
+PIPE="-pipe"
 
 
 # __FreeBSD_version is the best way to determine whether
diff --git a/auto/os/linux b/auto/os/linux
index abf2936..78ab3d1 100644
--- a/auto/os/linux
+++ b/auto/os/linux
@@ -4,7 +4,7 @@
 CORE_SRCS="$UNIX_SRCS $LINUX_SRCS"
 EVENT_MODULES="$EVENT_MODULES"
 
-CFLAGS="$CFLAGS -pipe"
+PIPE="-pipe"
 
 
 CC_TEST_FLAGS="-D_GNU_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE"
diff --git a/auto/os/solaris b/auto/os/solaris
index 7c2caf4..f1ac0f9 100644
--- a/auto/os/solaris
+++ b/auto/os/solaris
@@ -15,16 +15,24 @@
 case $PLATFORM in
 
     SunOS:5.[89]:* | SunOS:5.10:*)
-        CFLAGS="$CFLAGS -pipe"
+        PIPE="-pipe"
     ;;
 
     *)
-        # Solaris 7's gcc does not support "-pipe"
+        # Solaris 7's /usr/ccs/bin/as does not support "-pipe"
     ;;
 
 esac
 
 
+if [ $ZLIB_ASM != NO ]; then
+    echo "$0: error: the --with-zlib-asm=CPU option is not supported"
+    echo "on that platform"
+    echo
+
+    exit 1
+fi
+
 
 ngx_inc="sys/devpoll.h"; . auto/inc